NSFileWrapper's serializedRepresentation returns inappropriately large data - objective-c

Question

NSFileWrapper's serializedRepresentation returns inappropriately large data when the Cocoa framework, rather than only the Foundation framework is imported. How can I prevent serializedRepresentation from returning this huge data.
My Scenario:
I'm using packages, aka folders, to store data for an app on OS X.
The data returned by serializedRepresentation is a couple of orders of magnitude larger when Cocoa has been imported compared with when only Foundation has been imported.
When converting these files back into packages the resulting package appears to be identical.
This actual example package is 22KB:
folder: [
some.plist,
folder: [
1.png
]
]
With the Cocoa framework imported the file created from the data returned by serializedRepresentation is 3.2MB
With only Foundation imported the file created from the data returned by serializedRepresentation is 32KB

Answer 1

TL;DR:
Remove all the icons that the Cocoa implementation of NSFileWrapper adds.
Explanation and example:
The Cocoa framework adds some kind of icon to the files before returning the serializedRepresentation. This can make the resulting files very large.
To resolve this issue: manually remove the icon from each file.
Swift Example:
func removeIconsFromFileWrapper(wrapper: NSFileWrapper) {
wrapper.icon = nil
if wrapper.directory {
for directory in wrapper.fileWrappers!.values {
removeIconsFromFileWrapper(directory)
}
}
}
let thisFileURL = NSURL(fileURLWithPath: filePath)
if let fileWrapper = try?NSFileWrapper(URL: thisFileURL, options: NSFileWrapperReadingOptions.Immediate) {
removeIconsFromFileWrapper(fileWrapper)
let fileData = fileWrapper.serializedRepresentation
let newFileURL = thisFileURL.URLByAppendingPathExtension("extension")
do {
try fileData?.writeToURL(newFileURL, options: NSDataWritingOptions.AtomicWrite)
success = true
} catch {
// !!!: inform user that:
NSLog("the file \(newFileURL) could not be saved")
}
} else {
NSLog("the file could not be read")
}